Purpose
To subjectively and quantitatively compare the quality of 3 Tesla magnetic resonance imaging of the prostate acquired with a novel flexible surface coil (FSC) and with a conventional ...endorectal coil (ERC).
Methods
Six radiologists independently reviewed 200 pairs of axial, high-resolution T2-weighted and diffusion-weighted image data sets, each containing one examination acquired with the FSC and one with the ERC, respectively. Readers selected their preferred examination from each pair and assessed every single examination using six quality criteria on 4-point scales. Signal-to-noise ratios were measured and compared.
Results
Two readers preferred FSC acquisition (36.5–45%) over ERC acquisition (13.5–15%) for both sequences combined, and four readers preferred ERC acquisition (41–46%). Analysis of pooled responses for both sequences from all readers shows no significant preference for FSC or ERC. Analysis of the individual sequences revealed a pooled preference for the FSC in T2WI (38.7% vs 17.8%) and for the ERC in DWI (50.9% vs 19.6%). Patients’ weight was the only weak predictor of a preference for the ERC acquisition (
p
= 0.04). SNR and CNR were significantly higher in the ERC acquisitions (
p
<0.001) except CNR differentiating tumor lesions from benign prostate (
p
=0.1).
Conclusion
Although readers have strong individual preferences, comparable subjective image quality can be obtained for prostate MRI with an ERC and the novel FSC. ERC imaging might be particularly valuable for sequences with inherently lower SNR as DWI and larger patients whereas the FSC is generally preferred in T2WI. FSC imaging generates a lower SNR than with an ERC.
Repeated exposure to lipopolysaccharide (LPS) induces desensitization of hypothalamus–pituitary–adrenal axis (HPA) responses and hypophagia. We investigated the interplay between the neural ...circuitries involved in the control of food intake and HPA axis activity following single or repeated LPS injections. Male Wistar rats received a single or repeated i.p. injection of LPS (100 μg/kg) for 6 days and were subdivided into four groups: 6 saline, 5 saline
+
1 LPS, 5 LPS
+
1 saline and 6 LPS. Animals with a single exposure to LPS showed increased plasma levels of ACTH, CORT, PRL, TNF-α and also CRF mRNA in the paraventricular nucleus of the hypothalamus. These animals exhibited a reduced food intake and body weight associated with an increase of CART expression in the arcuate nucleus (ARC). Leptin plasma levels were not altered. On the other hand, repeated LPS administration did not alter ACTH, CORT, PRL and TNF-α, but it reduced leptin level, compared to single LPS or saline treatment. Furthermore, repeated LPS administration did not increase CRF or CART mRNA expression. Food intake and weight gain after repeated LPS injections were not different from saline-treated animals. There was no change in NPY and POMC mRNA expression in the ARC after single or repeated injections of LPS. In conclusion, desensitization induced by repeated exposure to LPS involves the blockade of HPA axis activation and anorexigenic response, which are both associated with an unresponsiveness of TNF-α production and CRF and CART expression in the hypothalamus.
To determine the risk for developing malignant melanoma and neurocutaneous melanocytosis (NCM) in patients with large congenital melanocytic nevi.
Follow-up data suitable for calculations were ...available on 160 patients in the New York University Registry of Large Congenital Melanocytic Nevi who had been free of known melanomas or NCM when entered into the Registry. The cumulative 5-year life-table risks for developing melanoma and NCM were calculated. The relative risk for developing melanoma, using a control general population reference group, was determined.
The 160 patients (median age at entry: 14 months) were followed prospectively for an average of 5.5 years. Three extracutaneous melanomas developed: 2 were in the central nervous system (CNS) and 1 was retroperitoneal. The 5-year cumulative life-table risk for developing melanoma was 2.3% (95% confidence interval CI:.8-6.6) and the relative risk was 101 (95% CI: 21-296). No melanoma occurred within a large congenital melanocytic nevus. Four patients developed manifest NCM, 2 with CNS melanomas. The 5-year cumulative life-table risk for developing NCM was 2.5% (95% CI:.8-7.2). Ten patients were excluded from the calculations because of preexisting disease on entry into the Registry: 5 with manifest NCM and 5 with melanomas (3 in large congenital melanocytic nevi, 1 in nonnevus skin, and 1 unknown primary).
Patients with large congenital melanocytic nevi are at increased risk for developing melanomas. There is also a significant increased risk for developing NCM. The high incidence of CNS involvement may influence decisions concerning treatment of the large congenital melanocytic nevi.
Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and ...MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH.
Although anaphylaxis has been considered a priority public health issue in the world allergy community, epidemiological data on morbidity and mortality remain suboptimal. We performed the first ...multicenter epidemiological study in French emergency departments (EDs). The study covered 7 EDs over a period of 1 year. The objectives were to identify areas that are amenable to change and to support ongoing national and international efforts for better diagnosis, management, and prevention of anaphylaxis.
Ours was a descriptive study based on data routinely reported to French institutional administrative databases from 7 French public health institutions in the Lorraine region between January and December 2015. Data were collected based on the anaphylaxisrelated codes of the International Classification of Diseases (ICD)-10, and cases were clinically validated as anaphylaxis.
Of the 202 079 admissions to the EDs, 4817 had anaphylaxis-related codes; of these, 323 were clinically validated as anaphylaxis. Although 45.8% were severe, adrenaline was prescribed in only 32.4% of cases. Of the 323 cases, 57.9% were subsequently referred for an allergy work-up or evaluation (after or during hospitalization), and 17.3% were prescribed autoinjectable epinephrine.
Our results highlight an urgent need for improved public health initiatives with respect to recognition and treatment of anaphylaxis. We flag key problems that should be managed in the coming years through implementation of national and international actions.
To evaluate the impact of computed b = 1400 s/mm(2) (C-b1400) vs measured b = 1400 s/mm(2) (M-b1400) diffusion-weighted images (DWI) on lesion detection rate, image quality and quality of lesion ...demarcation using a modern 3T-MR system based on a small-field-of-view sequence (sFOV).
Thirty patients (PSA: 9.5 ± 8.7 ng/mL; 68 ± 12 years) referred for magnetic resonance imaging (MRI) of the prostate were enrolled in this study. All measurements were performed on a 3T MR system. For DWI, a single-shot EPI diffusion sequence (b = 0, 100, 400, 800 s/mm²) was utilized. C-b1400 was calculated voxelwise from the ADC and diffusion images. Additionally, M-b1400 was acquired for evaluation and comparison. Lesion detection rate and maximum lesion diameters were obtained and compared. Image quality and quality of lesion demarcation were rated according to a 5-point Likert-type scale. Ratios of lesion-to-bladder as well as prostate-to-bladder signal intensity (SI) were calculated to estimate the signal-to-noise-ratio (SNR).
Twenty-four lesions were detected on M-b1400 images and compared to C-b1400 images. C-b1400 detected three additional cancer suspicious lesions. Overall image quality was rated significantly better and SI ratios were significantly higher on C-b1400 (2.3 ± 0.8 vs 3.1 ± 1.0, P < 0.001; 5.6 ± 1.8 vs 2.8 ± 0.9, P < 0.001). Comparison of lesion size showed no significant differences between C- and M-b1400 (P = 0.22).
Combination of a high b-value extrapolation and sFOV may contribute to increase diagnostic accuracy of DWI without an increase of acquisition time, which may be useful to guide targeted prostate biopsies and to improve quality of multiparametric MRI (mMRI) especially under economical aspects in a private practice setting.
Understanding how evolutionary history and the coordination between trait trade‐off axes shape the drought tolerance of trees is crucial to predict forest dynamics under climate change. Here, we ...compiled traits related to drought tolerance and the fast‐slow and stature‐recruitment trade‐off axes in 601 tropical woody species to explore their covariations and phylogenetic signals. We found that xylem resistance to embolism (P50) determines the risk of hydraulic failure, while the functional significance of leaf turgor loss point (TLP) relies on its coordination with water use strategies. P50 and TLP exhibit weak phylogenetic signals and substantial variation within genera. TLP is closely associated with the fast‐slow trait axis: slow species maintain leaf functioning under higher water stress. P50 is associated with both the fast‐slow and stature‐recruitment trait axes: slow and small species exhibit more resistant xylem. Lower leaf phosphorus concentration is associated with more resistant xylem, which suggests a (nutrient and drought) stress‐tolerance syndrome in the tropics. Overall, our results imply that (1) drought tolerance is under strong selective pressure in tropical forests, and TLP and P50 result from the repeated evolutionary adaptation of closely related taxa, and (2) drought tolerance is coordinated with the ecological strategies governing tropical forest demography. These findings provide a physiological basis to interpret the drought‐induced shift toward slow‐growing, smaller, denser‐wooded trees observed in the tropics, with implications for forest restoration programmes.
We compiled traits related to drought tolerance and the fast‐slow and stature‐recruitment trade‐off axes in 601 tropical woody species to explore their covariations and phylogenetic signals. Overall, our results imply that: (1) drought tolerance is under strong selective pressure in tropical forests, and TLP and P50 result from repeated evolutionary adaptation of closely related taxa; and (2) drought tolerance is coordinated with the ecological strategies governing tropical forest demography: slow and small species tend to be more tolerant to drought.
Adult T-cell leukemia-lymphoma (ATL) is a distinct peripheral T-lymphocytic malignancy associated with a retrovirus designated human T-cell lymphotropic virus type I (HTLV-1). The diversity in ...clinical features and prognosis of patients with this disease has led to its subclassification into the following four categories: acute, lymphoma, chronic, and smoldering types. The chronic and smoldering subtypes are considered indolent and are usually managed with watchful waiting until disease progression, analogous to the management of some patients with chronic lymphoid leukemia (CLL) or other indolent histology lymphomas. Patients with aggressive ATL generally have a poor prognosis because of multidrug resistance of malignant cells, a large tumor burden with multiorgan failure, hypercalcemia, and/or frequent infectious complications as a result of a profound T-cell immunodeficiency. Under the sponsorship of the 13th International Conference on Human Retrovirology: HTLV, a group of ATL researchers joined to form a consensus statement based on established data to define prognostic factors, clinical subclassifications, and treatment strategies. A set of response criteria specific for ATL reflecting a combination of those for lymphoma and CLL was proposed. Clinical subclassification is useful but is limited because of the diverse prognosis among each subtype. Molecular abnormalities within the host genome, such as tumor suppressor genes, may account for these diversities. A treatment strategy based on the clinical subclassification and prognostic factors is suggested, including watchful waiting approach, chemotherapy, antiviral therapy, allogeneic hematopoietic stem-cell transplantation (alloHSCT), and targeted therapies.
Evolution of a minimal cell Moger-Reischer, R Z; Glass, J I; Wise, K S ...
Nature (London),
08/2023, Letnik:
620, Številka:
7972
Journal Article
Recenzirano
Odprti dostop
Possessing only essential genes, a minimal cell can reveal mechanisms and processes that are critical for the persistence and stability of life
. Here we report on how an engineered minimal cell
...contends with the forces of evolution compared with the Mycoplasma mycoides non-minimal cell from which it was synthetically derived. Mutation rates were the highest among all reported bacteria, but were not affected by genome minimization. Genome streamlining was costly, leading to a decrease in fitness of greater than 50%, but this deficit was regained during 2,000 generations of evolution. Despite selection acting on distinct genetic targets, increases in the maximum growth rate of the synthetic cells were comparable. Moreover, when performance was assessed by relative fitness, the minimal cell evolved 39% faster than the non-minimal cell. The only apparent constraint involved the evolution of cell size. The size of the non-minimal cell increased by 80%, whereas the minimal cell remained the same. This pattern reflected epistatic effects of mutations in ftsZ, which encodes a tubulin-homologue protein that regulates cell division and morphology
. Our findings demonstrate that natural selection can rapidly increase the fitness of one of the simplest autonomously growing organisms. Understanding how species with small genomes overcome evolutionary challenges provides critical insights into the persistence of host-associated endosymbionts, the stability of streamlined chassis for biotechnology and the targeted refinement of synthetically engineered cells
.
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